Along with the development of higher levels of integration in integrated circuits, power requirements have increased. This is particularly true with current microprocessor and associated integrated circuits or chips recently developed and now being developed. These chips, which are operating at higher speeds, require and consume greater amounts of power than previously required.
In a typical computer system, a large printed circuit board known as a motherboard is provided. The motherboard contains a certain number of basic components and is supplied with voltage from a power supply, typically at a higher DC voltage (e.g., 12 volts) than required by the components on the motherboard. The motherboard includes connectors for daughter boards which can be plugged in to provide different capabilities for the computer. Such boards, for example, may provide an interface to disk drives and CD ROMs, modem interfaces for local area networks, etc. Typically, these daughter boards operate from the 12 volts which is supplied from the motherboard, or from reduced voltages such as 5 volts. Power consumption of the daughter boards is typically not extremely high (e.g. &lt;20 W).
Current processors however have been designed to operate at lower voltages, e.g., 3.3 volts. Because of the increased capability and speed of these processors, they consume a large amount of power despite their lower voltage. Their operation at a lower voltage requires a localized dc-to-dc power converter to reduce the motherboard voltage. Typically, this dc-to-dc power converter is soldered to the mother board or plugs into a connector on the motherboard. The lower voltage is then conducted through conductors or printed circuit traces on the motherboard to a connector for the component requiring the lower voltage, e.g., a processor. This same connector may also provide signal connections.
In a number of state of the art systems, one or more processors, and in some cases associated integrated circuit deviecs, are mounted on a board or module. This module then plugs into a connector on the motherboard. Since the voltage required by the processor is lower, and the power consumption is high, the currents which must be supplied to the module become particularly large. As a result, it is difficult to establish a low resistance, low inductance path on the motherboard from the dc-to-dc converter board to the module. This is particularly true because the prior art arrangement requires that the high current pass through two connectors: one from the dc-to-dc converter into the motherboard and another connector from the motherboard through the module connector to the module. Also, the prior art arrangement may present difficulties in manufacture because the dc-to-dc converter becomes an additional component that must be tested with the remaining components on the motherboard.
Thus, there is the need for an improved arrangement for delivering power to a power consuming module requiring high amounts of power at a lower voltage, which voltage must be converted from a higher voltage.